The traditional miller processes the cutter by utilizing a cutter carrier of a cutter holder, and one end of the cutter carrier has an arbor hole for fixing a cutter and the other end is fixed at a drive shaft, wherein the cutter carrier is driven by the drive shaft to rotate rapidly so that the cutter can drill, cut or grind the object. However, in the production process of the cutter carrier, because the cutter carrier is unbalanced owing to the standards (such as SK, BT, CAT, HSK) and types (such as lateral fixing type, face miller) of the cutter carrier itself and also the variation of the production accuracy and of the clamping precision of carrier, and the deformation caused by heat treatment, the two ends of the cutter carrier might have a core offset to cause an unbalance. If this unbalanced cutter carrier is used on the cutter holder, then the faster the rotation speed, the more obvious the vibration caused by the unbalanced centrifugation. In particular, the rotation speed of the modern miller can achieve tens of thousands of circles in one minute so that the unbalanced cutter carrier might cause a bigger vibration to make an error in the cutting of the object, to reduce the life time of the cutter, and more seriously, also to damage the drive shaft of the cutter holder. If it needs to buy a new carrier holder, the cost is proportion to the precision for manufacturing the cutter, and since the cutter and holder have different fabrication standards and manufacturing precision, the combination thereof might need to pay more attention to the balance correction therebetween. Furthermore, after a new cutter is clamped by a balanced holder, because the cutter always has a asymmetric shape and the holder might have other smaller components (such as bolt, clamping screw, bearing, collet etc.), each time a different cutter is used, a dynamic balance is needed.
For improving the defects described above, usually, the cutter carrier is firstly checked by a dynamic balance corrector to find the offset center of gravity thereof, and then, the problem caused by the unbalanced center of gravity of the cutter carrier will be corrected by the following methods of:
1. drilling one side of the cutter carrier which is closer to the center of gravity for reducing the weight at this side; 2. adding a mass on one side of the cutter carrier which is farther from the center gravity for balancing two sides of the carrier; and 3. mounting a movable protrusion on the carrier for adjusting the position of the gravity center slightly and then fixing the protrusion on the carrier after confirming a balance thereof so as to achieve a dynamic balance correction.
Although the methods above are workable, drilling is a destruction which might influence the using life of the cutter carrier and also may need a lot of accuracy as processing. As to the protrusion adjusting, although this method does not damage the carrier, the adjusting time becomes longer and the position thereof still might be moved as fixing the protrusion so that the balancing position must be found again, which actually takes a lot of time and is inconvenient. References can be found in R.O.C. Patent Publication Nos. 570853 and 538846.